Looper mounting for sewing machines



Aug. 20, 1929. K. MAIERT] I LOOPER MOUNTING FOR SEWING MACHINES 2 Sheets-Sheet F iled Nov. 14, 192'? Aug. 20, 1929. K, MAIER 1,725,591

LOdPER MQUNTING FOR SEWING MACHINES Filed Nov. 14, 1927 2 Sheets eat 2 Patented Aug. 20, 1929.

UNITED STATES FATENT FFKIE.

KARL MAIERpOF STUTTGAR-T, GERMANY, ASSIGNOR T UNION SPECIAL MASCHIN- ENFABRIK, G. M. B. H., OF STUTTGART, GERMANY.

LOOPER MOUNTING FOR SEWING MACHINES.

Application filed November 14, 1927, Serial No. 233,278, and in Germany Ilecember 22 1826.

The invention relates to new and useful improvements in looper mountings for sewing machines, and more particularly to the mounting for a looper in an overedge sewing mechanism.

An object of the invention is to provide a mounting for a looper of the above type wherein the support for the looper may be shifted so as to varyv the distance of the setting of the point of the looper from its axis of oscillation;

A further object of the invention is to provide a looper mounting of the above type wherein the looper maybe shifted a comparatively small distance and held in its set position by the shifting means when said shifting means is locked against movement'.

These and other objects will in part be obvious and will in part be hereinafter more fully described. In the drawings which show by way of illustration one embodiment of the invention:

1 Figure 1 is an end view of a portion of the sewing machine embodying the improvements; i

Fig. 2 is a detail partly in perspective showing the overedge looper and the supporting and operating means therefor;

Fig. 3 is a plan view of the parts shown in Fig.2; I p

Fig. 4c is a view partly in s de elevation and partly in section longitudinally of the support for the overedge looper;

Fig. 5 is a sectional view on the line 5-5 of Fig. 4:. p

The invention is directed broadly to a looper mounting for sewing machines, and

more particularly to the mounting for a looper in an over-edge stitch-forming mech anism. The purpose of the invention is to provide a mounting for a looper which permits the looper point to be set at different distances from its axis of oscillation, so that the looper may be properly positioned t0 cooperate as to position and in timing with the needle and an under-looper if desired. This purpose is accomplished by mounting the looper carrying arm on a bushing which is located eccentri'cally 0n the supporting shaft for the looper. This bushing is preferably split, and likewise the integral collar at the inner end of the arm carrying the looper is split and a clamping bolt is pro- .vided for drawing this collar into clamping leased the bushing may be shifted and the shifting of the bushing will vary the distance between the point of the looper and the, axis of the support for the looper.

Referring more in detail to the drawings,

a portion of the sewing machine hasbeen shown including a supporting base 1 which carries bearings 2 and 3 in which is mounted mounted a looper supporting shaft 4:. The looper supporting shaft 4 inclines downwardly from the rear of the machine toward the front thereof. The purpose of this inclination is to cause the over-edge looper carried by this shaft to swing in a plane inclined to the plane of the work support, and thus pass from a point in rear of the under-looper to a point in front of the needle when over the work support.

The looper shaft 4 is provided with a projecting arm 5 carrying a ball stud. Alink 7 is provided with a head 6 which engages the ball stud on the end of the arm 5. This link 7 also has a head 8 which engages-a ball stud carriedby a crank 10 on the end of the actuating shaft 9. As this shaft 9 rotates, the link 7 will impart oscillations t0.

the looper supporting shaft/i.

Mounted on thelooper supporting shaft 4 is an eccentric bushing 11. This eccentric bushing 11 serves as a support for the hub or collar 12 carrying. the looper supporting arm 13. The bushing 11 is split as indicated at 14. The collar or hub 12 is likewise split and a clamping bolt 15 passing through projecting ends carried by the collar operates to draw the split collar into gripping contact with the split bushing, and in turn causes the split bushing to grip the looper shaft t. This clamping bolt 15 thus firmly clamps the arm 13' carrying the looper to the looper supporting shaft 4. It will be noted from thread-carrying type.

Figs. 1 and 2 that there are two clamping bolts 15.

The bushing 11 extends beyond the hub or collar 12 and is provided with a head 16 which in turn carries a scale or graduation 17. The arm 5 is carried by a collar which is fixed to the looper shaft a by suitable screws, and on this collar is a line 18 adapted to cooperate with the scale or graduations on the hub 16 of the bushing 11. The hub of the bushing 11 adjacent the scale or graduations is formed with an enlarged rib portion 19 which is knurled. WVhen the clamping bolts 15 are released, then the operator may, by

; grasping the knurled rib 19, rotate the split bushing on the looper supporting shaft, thus shifting its position on the shaft. WVhen the clamping bolts are again tightened the parts will be rigidly clamped together on the looper shaft, and thus held in the new set position.

The looper is indicated at,21 in the drawings and the looper point isindicated at 20. The looper shown on the drawings is of a It will be understood, of course, that the looper may have a hook on the end thereof and be of a non-threadcarrying type and still cooperate with a looper located beneath the work support and with the needle above the work support.

The invention has to do with the mounting of the looper regardless of whether it is a threaded looper or a hook carrying a loop of thread in its stitch forming cycle of operation. In the drawings there is shown a needle bar 22 carrying an eye-pointed-needle and the presser bar is indicated at 23. In the operation of the stitch forming mechanism it is understood, of course, that the needle after passing through the material throws out its loop, and an underthreaded looper or hook cooperates with the needle, and the looper indicated in the drawings cooperates first with the underlooper or hook and then with the needle. By shifting the eccentric bushing the point of the looper may be set at different distances from the axis of the looper shaft 4. lVhen the eccentric bushing 11 is turned in a clockwise direction as viewed in Fig. 2, the looper point will be shifted from the position indicated at I to the position indicated at II. Onthe other hand, if the bushing is turned in a counterclockwise direction, the looper point will be carried to the position indicated at III.

It will be noted that the means for shifting the position of the looper point is a part of the looper mounting. shifting is brought about by the turning of an eccentric bushing, the looper point may be moved through very small distances and at no time is the control of the looper lost. In other Words, ,the looper is never released from its looper support, but maintains its Inasmuch as the support thereon and is shifted radially of the support. It will also be noted that this means which shifts the looper point from one set position to another when properly clamped so that it cannot move, will hold the looper in its set position. It will be noted from the above disclosure that the means for shifting the looper from one set position to another operates to positively move the looper, and without losing its control of the looper. 7

It is obvious that the looper mounting may be used in connection with loopers in other types of mechanisms than that shown and described. It is also. obvious that minor changes in the detail of construction and the arrangement of parts may be made without departing from the spirit of the invention as set forth in the appended claims.

What is claimed as new is:

1. The combination of a looper and a mounting therefor including an arm on which said looper is supported, a looper shaft, an eccentric bushing surrounding the shaft and carrying said arm, means for clamping said arm and bushing to said shaft, andmeans whereby said bushing may be shifted for shifting the set position of the point of the looper radially of the axis of the shaft.

2. The combination of a looper, a looper shaft, a bushing mounted on said looper shaft, an arm having a clamping collar surrounding said bushing and carrying said looper, said bushing being split whereby said clamping collar may firmly secure said arm and bushing to said shaft, said bushing having means whereby the same may be adjusted for shifting the position of the point of the looper radially relative to the axis of the shaft.

3. The combination of a looper, a looper shaft, a bushing mounted on said looper shaft, an arm havlng a clamping collar sun.

rounding said bushing and carrying said looper, said bushing being split whereby said clamping collar may firmly secure said arm and bushing to said shaft, said bushing having means whereby the same may be adjusted for shifting the position of the point of the looper radially relative to the axis of the shaft, an arm attached to said shaft for oscillating the same, said arm being carried by a collar secured to'the shaft adjacent the end of the bushing, said bushing having a scale thereon adapted to cooperate with a l1ne on the collar carrying said arm for indicating the position of the looper point relative to the axis of said shaft.

4. The combination of a looper, a looper shaft, a split bushing eccentricallv mounted on said shaft, an arm having a clamping collar surrounding said bushing and carrying said looper, said bushing having a knurled rib formed thereon at one side of said collar, whereby said bushing may be vices for supporting said arm on said shaft shifted on the shaft, and clamping means including means for positively shifting the for clamping said collar and said bushing looper radia-llv toward and from the axis of 10 to said shaft. the shaft and for holding said looper in its 5 5. The combination of a looper and a shifted positions.

mounting therefor comprising a supporting In testimony whereof, I aflix my signature. armearrving said looper, a looper shaft, de- KARL MAIER. 

